/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile.editor;

import proguard.classfile.*;
import proguard.classfile.attribute.*;
import proguard.classfile.attribute.visitor.*;
import proguard.classfile.util.SimplifiedVisitor;

/**
 * This AttributeVisitor adds the line numbers of all line number attributes that it visits to the given target line
 * number attribute. It ensures that the sources of the line numbers are preserved or set.
 */
public class LineNumberInfoAdder extends SimplifiedVisitor implements AttributeVisitor, LineNumberInfoVisitor {
    private final LineNumberTableAttributeEditor lineNumberTableAttributeEditor;

    private String source;

    /**
     * Creates a new LineNumberInfoAdder that will copy line numbers into the given target line number table.
     */
    public LineNumberInfoAdder(LineNumberTableAttribute targetLineNumberTableAttribute) {
        this.lineNumberTableAttributeEditor = new LineNumberTableAttributeEditor(targetLineNumberTableAttribute);
    }

    // Implementations for AttributeVisitor.

    public void visitAnyAttribute(Clazz clazz, Attribute attribute) {}

    public void visitLineNumberTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute,
        LineNumberTableAttribute lineNumberTableAttribute) {
        // Remember the source.
        source = clazz.getName() + '.' + method.getName(clazz) + method.getDescriptor(clazz) + ':'
            + lineNumberTableAttribute.getLowestLineNumber() + ':' + lineNumberTableAttribute.getHighestLineNumber();

        // Copy all line numbers.
        lineNumberTableAttribute.lineNumbersAccept(clazz, method, codeAttribute, this);
    }

    // Implementations for LineNumberInfoVisitor.

    public void visitLineNumberInfo(Clazz clazz, Method method, CodeAttribute codeAttribute,
        LineNumberInfo lineNumberInfo) {
        // Make sure we have a source.
        String newSource = lineNumberInfo.getSource() != null ? lineNumberInfo.getSource() : source;

        // Create a new line number.
        LineNumberInfo newLineNumberInfo =
            new ExtendedLineNumberInfo(lineNumberInfo.u2startPC, lineNumberInfo.u2lineNumber, newSource);

        // Add it to the target.
        lineNumberTableAttributeEditor.addLineNumberInfo(newLineNumberInfo);
    }
}
